Over the coming weeks, our staff will be posting our customer's model specific installation questions as well as our answers and guidance from our notes. Eventually, this will create a searchable knowlege base that may be of help to people in similar situations.

Feel free to post your situation and what you did to overcome it. We'll chime in if we have something to add or if we know that your solution might not work with another known configuration.

8 years, 3000 plus exhaust installations and we still run into new "challenges"

Answer: Original 2 Blade Hartzell propeller installations from before 2008 are not compatible with the Power Flow Exhaust System. Our installation instructions make specific reference to this.

However, in October 2007, Hartzell certified a new version of their 2 blade aluminum propeller that has been specifically tested with the Power Flow Exhaust and found to be compatible. Available through Hartzell's "Top Prop" program or from Power Flow Systems, the STC'd package includes a new propeller assembly, new hub and new spinner. The current retail price is $7,495 plus s/h.

In addition to the aluminum propeller, Hartzell has certified their new 2 blade composite propeller under the same STC. This propeller is also compatible with the PFS exhaust. It retails for $11,295 plus s/h.

I have an MT governor on my DA40. Is this compatible with the Hartzell Propeller?

I have an MT governor on my DA40. Is this compatible with the Hartzell Propeller?

I have been in contact with the Engineering people at both Diamond and Hartzell regarding compatibility on the governor. Some background for you: The DA40 used to come with the a Woodward Governor. That is being phased out in favor of an MT governor. The MT governor is part of the type certificate of the DA40 and so any STC'd modifications, unless specifically exempting this governor or listing it as a required item for the STC, should be ok from a legal "can I install it" point of view. The new Hartzell STC does not specifically exempt this governor or list the Woodward as a required item.

So, to answer the question, the new Hartzell propellers (2 blade alum. and 2 blade composite) should be just fine if you have either the Woodward or the MT governors.

To my knowledge, Hartzell has not certified a 3 blade composite for this aircraft.